Boiler construction



Jan. 30, 1934. .1. A. FORD BOILER CONSTRUCTION Filed April 1, 1931 3Sheets-Sheet 1 INVENTOR 1.7272165 i'ard ATTORNEYS- Jan. 30, 1934. J. A.FORD 1,945,349

BOILER CONSTRUCTION Filed April 1, 1951 3 Sheets-Sheet 2 JNVENTOR gjbmesfll araf .TTORNEY Jan. 30, 1934. J. A. FORD 1,945,349

BOILER CONSTRUCTION Filed April 1, 1931 5 Sheets-Sheet 3 INVENTOR J'amesfi. Ford Patented Jan. 30, 1934 PATENT oF'FIc UNITED STATES 8 Claims.

The present invention relates to furnaces of the type adapted for use inconnection with the heating of residences and like structures, and theprincipal object is to provide a furnace of this type that is simple inconstruction, economical in operation, and that will have a relativelylong life.

Other objects of the invention are to provide a furnace of theresidential heating type constructed substantially entirely of sheetmetal; to provide a furnace of this type having a novel construction ofcombustion and heat interchange chambers; to provide a furnace of thetype described having a lower Water header connected L; to the mainwater header by water passages of novel form; to provide waterpassagesin the heat interchange chamber of such formand so arranged as toextract a maximum amount of heat from the products of combustion duringpassage so through the heat interchange chamber; and to provide suchwater passages of elongated sections and so arranged that the side wallsare in generally radial disposition with respect to the outlet openingof the heat interchange chamber.

Other objects are to provide water passages of novel form for the heatinterchange chamber of a furnace; and to provide a novel form ofconstruction for such passages.

The above being among the objects of the pres--' ent invention, the sameconsists in certain features of construction and combinations of partsto be hereafter described with reference to the accompanying drawings,and then claimed, having the above and other objects in view. In theaccompanying drawings which illustrate suitable embodiments of thepresent invention, and in which like numerals refer tolike partsthroughout the several different views Figure 1 is a sectional view of aboiler embodying features of my invention,

Figure 2 is a sectional view of a boiler similar to that shown in Figure1, taken on an angle thereof and illustrating a modified form of myinvention, 7

Figure 3 is a sectional view of the structure shown in Figure 1 taken onthe line 3-3 thereof,

Figure 4 is a sectional view of the structure, shown in Figure 1, takenon the line 4-4 thereof, r0 Figure 5 is a sectional View of thestructure shown in Figure 1, taken on the line 55 thereof,

Figure 6 is a view similar to that of the structure shown in Figure 5,illustrating-a modified form of my invention,

Figure '7 is an enlarged sectional view, in elevation, of theinterchanger shown in Figure 4 illustrating a modified form thereof, H f

Figure 8 is an enlarged planview of the smoke box shownin Figures 1, 4,5 and 6,

Figure 9 is a sectional view of the structure shownin Figure 8, taken onthe line 9-9 thereof, Figure 10 is a broken enlargedview of a section ofthe structureshown in Figure 4, H Figure 11 is an enlarged brokensectional View of a separate fluid conductor illustrated in Figure 2, IFigure 12 is a view of the structure similar to ihat shownin Figure 11illustrating a modified form which the structure may assume, Figure 13is an end View of thestructure shown inFigures 11 and 12, illustratingthe method of attaching the separate conductors theretO and Figure 14 isa view of the structure shown in Figure 12 taken on the line 1i1 ithereof,

While the present invention may be adapted to either hot air, steam orwater furnaces for residential uses, I have designed it particularly foruse in connection with steam or hot water installations, andconsequently the specific embodiments of the invention disclosed in thedrawings are illustrated as of the latter type. Furthermore, while thedesign of the furnace is adapted pariicularly to fabrication from sheetmetal, boiler plate or the like, it will be apparentin the followingspecification that as far as many of the main features of constructionare concerned, such features may be incorporatedin a furnace which maybe constructed'in whole or in part of cast metal. V

. Referring to the accompanying drawings, I show my furnace as beingprovided with a circular base 16 forming an ash box. The front wall ofthe base 16 is provided with an opening in which a square frame 21 isreceived, and to which adoor' (not shown) may be secured where coal isto be employed in the furnace, or through, which an oil burner may beinserted when oil burners of the type which are introduced into theashpit are to be employed.

The upper end ofthe base 16 is provided with an inwardly extendingannular member 22, suitably welded thereto and forming a seat forreceiving the boiler portion of the furnace. The boiler includes anouter cylindrical shell 15 preferably formed from sheet metal andsuitably, welded together, and an inner concentric shell 30 spaced fromthe outer shell 15 and preferably formed from sheet metal suitablywelded together. The lower end of the shells 15 and 30 are secured andsealed together by an annular sheet member 24 welded thereto. The upperend of the shell 15 is provided with an upwardly curved head 44 suitablywelded thereto and which, in'turn, is provided with a relatively largecentral opening in which the threaded collar 45 is welded for receivingthe steam or water outlet pipe of the furnace. The shells 15 and 30 areprovided at their front with aligned openings 25 and 43 respectively, inwhich is received a door frame 27 which is secured and sealed thereto bya suitable welding operation.

The inner shell 30 terminates at its upper end in downwardly spacedrelation with respect to the upper end of the outer shell 15, and therear Wall of the outer shell 15 is provided with an opening 26, theupper edge of which is substantially flush with the upper edge of theinner shell 30. The upper end of the inner shell 30 is closed by a topheader member 35 of the shape indicated in Figure 5 and which is ofgenerally circular formation in plan view with the exception that it isprovided at its back with an extending portion 41 of a widthcommensurate with the width of the opening 26 into which it projects andwhere it is welded to the outer shell 15.

Downwardly spaced from the upper header 35, is an intermediate header 39of the same general shape as the upper header 35 with the exception, asillustrated in Figure 4, that it is cut back from contact with the innershell 30 for approximately 180 degrees over its forward side. Therearwardly extending portion 42 of this intermediate header 39 extendsinto flush relationship with respect to the lower edge of the opening 26and is welded to the outer shell 15 at that location. The side walls ofthe inner shell 30 between the headers 35 and 39 are slit centrally ofthe opening 26 and outwardly bent along the margins of the headers 35and 39 to which they are suitably welded, and into contactwith the sidesof the opening 26 at which location the free ends of such portions arewelded to the sides of the opening 26 in the outer shell 15. In thespace thus formed between the upper and intermediate headers 35 and 39,and which is utilized as an interchange chamber, is arranged a pluralityof vertically extending tubular members 49, which will be describedlater in detail, and which project through these headers to form a waterpassage therebetween and are suitably welded to each thereof.

Spaced a suitable distance below the intermediate header 39 is a lowerheader 38 which is of the same shape as the header 39 with the exceptionthat it has no extension portion corresponding to the portion 41 of theheader 39. The inner shell 30 is cut away over its rear half between theheaders 38 and 39 for a distance of 180 degrees, and extending betweenthe headers 38 and 39 from one side of the inner shell 30 to theopposite side, and following the contour of the front half of theheaders 39 and 38 is a member 32 welded to the cooperating parts overits entire length. The lower header 33 is welded over the rear 180degrees of its circumference to the inner shell 30 at the lower edge 31of this cut out portion.

From the above it will be apparent that between the headers 38 and 39 alower water header is provided which communicates with the upper waterheader, between the upper header 35 and the cover 44 for the outer shell15, not only through the passages within the tubular members 49, butalso between the outer shell 15 and the inner shell 30 for that portionof the rear 180 de-.

grees of the furnace not occupied by the extensions 41 and 42 on theheaders 35 and 39. It will also be apparent that a combustion chamber 17is formed below the lower header 33 and communicates with the heatinterchange chamber between the headers 35 and 39 through a semi-annularpassage 36 formed between the member 32 and the inner shell 30 over thefront half of the latter. It will also be apparent that the semi annularshape of the passageway 36 between the combustion chamber 17 and theinterchange chamber acts to spread the products of combustion, inpassing from one to the other, into a relatively wide sheet conducive tooptimum heat interchange conditions when properly taken ad-.

vantage of.

The construction of the tubular members 49 to take proper advantage ofthe form in which the combustible mixture is introduced into theinterchange chamber, will now be described. As best illustrated inFigures 4 and 5, the members 49 in section are elongated, and each areprovided with one relatively wide rounded end and one relatively narrowrounded end. All of the members 49 are arranged in a fan-like or radialrelation with respect to the outlet for the products of'combustion fromthe furnace, and their relation of width to length is such, and theirposition in the heat interchange chamber is such, as to provide betweenthem a plurality of relatively narrow passages 52, of substantiallyconstant width, for the passage of products of combustion through theheat interchange chamber.

When the sides of the smoke box are removed in a manner which will beexplained hereinafter, a brush or other cleaning instrument may beinserted between each pair of the tubes 49 and the inner surface of theheat interchanger to thereby reach and clean all points of the surfacesof the tubes and the inner surface of the interchanger. By removing allof the soot in this manner from the exchanging surfaces of the heatinterchanger, the heat is thereby readily transferred through the wallsof the tubes and interchanger, from the product of combustion flowingtherethrough to the fluid passing within the tubes 49.

Referring particularly to Figs. 3 and 4, it will be noted that thepassage 36 connecting the combustion chamber to the heat interchanger isarcuate in shape and encompasses the entire width of the combustionchamber 17 to enable the products of combustion to be delivered to theheat interchanger in such manner that the flow of the combustionparticles therethrough to the outlet thereof, will be uniform betweenthe passages provided by the spaced tubes 49. This uniform flow of thecombustion particles across the elongated sides of the tubes 49, readilycauses the heat remaining in the products of combustion to be conductedtherefrom to the fluid to be heated, with a result that'the stacktemperature is retained below a value which would be effective forappreciably raising the temperature of the fluid, and this goes toincrease the efliciency of my boiler.

The tubes 49, when extended in dimensions to conform to the dimensionsof larger furnaces, are subject to greater strains than in the case ofsmaller furnaces, and in order to guard against their collapse, I haveshown in Fig. 6 the sides thereof as being of arcuate shape to increasetheir resistance to pressure. The dispositions of the sides relative toeach other and to a point at the mouth of the interchanger has beenretained, as will be noted from Fig. 6, to provide uniform passages forthe combustion gases which are readily accessible from the mouth of theinterchanger.

In Fig. 7, I have illustrated another method for strengthening the sides52 of the tubular member 49, that of constructing the tubular member intwo sections having inturned flanges 53 thereon which are weldedtogether at 54 to effect a unit tubular structure. The flanges and thewelded joints brace the sides 52 to increase their resistance topressure differences between the inner and outer fluid. A weld may alsobe provided on the inner abutting edges of the flanges 53 to increasethe strength of the joint and to decrease the possibility of a fluidleaking therethrough.

In order to have the mouth of the interchanger readily accessible forcleaning purposes, I have constructed the smoke box 19 in such manner asto have the encompassing side wall 55 thereof readily removable. Theends 41 and 42 of the headers 35 and 39, and the outwardly bent portionsof the inner shell 30 between them, project through the opening 26 as asubstantially rectangular end frame 56 which is provided with a collar57 which is slidable over the end 56 and which is provided with inwardlysloping surfaces 58 on its inner side edges. A pair of plates 59 arewelded, or otherwise attached, to the top and bottom of the squarecollar 57 and a strap 61 is attached to the inner edge of the bottomplate 59 for effecting a shoulder inwardly of the edge of the plate.

The top plate 59 is provided with an opening 62 through which a smokebreaching 63 extends and is retained against the inner surface of theplate 59 by a ring 64 which is supported against a flange 65 of thesmoke breaching 63 and the inner surface of the top plate 59 by rivetsor other suitable means. The outer edge of the ring 64 forms a shoulderfor the rear portion of the upper plate, and straps 66 are attached tothe underside of the top plate in continuation of the ring 64 foreifecting shoulders along its side edges. The shoulders effected by thering 64 and the straps 65 are offset inwardly on the underside of theupper plate 59 in the same manner as the strap 61 is offset inwardly onthe upper side of the bottom plate 59. Y

The shoulders thus effected on the plate 59, receive the encompassingmember 55 which extends thereabout andwhich is provided with inturnedflanges 67 on its ends for engaging the sloping surfaces 58 of thecollar 57 for retaining the member 55 in sealed relation with theshoulders. A handle 68 is mounted on one side of the member 55 adjacentto a flange 6'7 for the purpose of effecting the release of the flangeand therefore the entire encompassing member, as shown in Fig. 5 in dotand dash line, to have the discharge opening of the interchangerreadilyaccessible to an operator.

After the walls of tubes 49 of the interchanger have been cleaned andthe soot removed from the inner surface of the interchanger, thedischarge opening therethrough is closed by engaging the flange 67 onone end'of the encompassing member 55, with a surface 58 on the collarand drawing the member about the shoulders, effected by the strap 61,the ring 64 and the member 66, until the flange on the opposite end ofthe encompassing member engages the opposite surface 58 of the collar.By disassembling the sides of the smoke box in this manner, the mouth ofthe interchanger is made accessible to an operator and the cleaning toolmay be swung through such an angle that all points of the inner surfaceof the interchanger may be reached'thereby. In Fig. 10, I have shown anenlarged view of the sloping surface 58 of the collar 57 which isengaged by the flange 67 of the encompassing member 55. a

In connection with my furnace, it will, of course, be obvious that an.insulating covering such as 29 may be provided for preventing a loss ofheat from the furnace by transfer to the surrounding air, and thatsuch'insulation may be provided with a fabric or metal enclosure such as4'7,

if desired.

It will also be apparent that any suitable means may be provided forsupporting grates when coal is to be used as fuel. As a means ofillustration, I have shown grate supports48. welded to the sides of theash box 16, the grates being indicated by dotted lines at 23.

Referring to Fig. 2, I have shown a separate circulating system 70provided in the boiler 20, the conducting tube '71 thereof forming adelivery and return circuit for a fluid to a vicinity above the lowerheader 38 and below the intermediate header 39, which area is thehottest part of the boiler. The purpose of the second fluid conductingcircuit is to heat water which is to be employed for washing, bathing orother purposes, without requiring a second boiler or heating device.

I have shown the structure enlarged in Figs. 11 and 12 as including athird threaded aperture 73 through the side of the fluid container 15,in which a plug 74 is threaded for sealing the aperture against theegress of the fluid; A'pair of shouldered apertures 75 are provided inthe plugs '74, the shoulders of which engage the flanged ends of thetube 71. Outwardly from the shoulders, the aperture is threaded at '76,for engaging the thread 77 of a nipple 78 which is screwed therein withits inner end tightly engaging the flanged end of the tube 71 for thepurpose of forming a seal therewith. In this construction the lowernipple 78 constitutes a conductor for the cold water which passesthrough the tube '71 within the boiler 20 and outwardly through theupper portion of the tube and the upper nipple '78 to be conducted to ahot water storage tank. It willbe noted that the fluid in the separatecircuit is conducted through the nipples 78 to and fromthe tube 71independent of the plug 74. The plug is employed to removably supportthe circuit in the side of the boiler and to provide shoulderedapertures in which the direct engagement between the nipples and the flnged ends of the tubes is effected.

In Fig. 12, I have shown the tube 71 as being bent back upon itself at'79 and reversely bent at 30 and then outwardly at 81 to therebyincrease the length of the tube and decrease the amount of time that thewater need be encompassed by the fluid of the boiler to raise itstemperature a predetermined amount. The tubes are constructed to have anoverall outside diameter which is less than the diameter of the aperture'73 in order that the tube may be inserted within the boiler along withthe plug '74 which is threaded into aperture 73. In Fig. 14, I'haveshown a cross section of the tube which has been bent back upon itselfas shown in Fig. 12 to disclose the relation of the various-elements 79,80 and 81 thereof when positioned within the confines of the aperture'73. I

In Fig. 13, I have shown a pair of apertures 82 which are providedthrough the plug 74 along with the apertures 75 which receive thenipples '78. The aperture 82 on the left handportionof the plug isclosed by a second plug 83, while the aperture 82 on the right hand.side of the plug is provided with an elbow 84 to which a conductor, 85is connected. The elbow 84 directly communicates with the fluid withinthe boiler which may be conducted therefrom by the pipe 85 to provide aconvectional flow of the fluid through the boiler, or for otherpurposes.

While I have described and illustrated several embodiments of myinvention, it will be apparent to those skilled in the art that variouschanges, omissions, additions and substitutions may be made thereinwithout departing from the spirit and scope of my invention, as setforth in the accompanying claims.

I claim as my invention:

1. A heat interchanger for a boiler including, in combination, anenclosure member having a chamber. and being provided with a wideopening in one end, constituting a passage for the ingress of thecombustible gases, and an oppositely disposed opening for the egress ofthe gases, hollow members extending through said enclosure member,having arcuate sides, the adjacent sides of adjacent members beingstruck from the same center and arranged to provide passages havinguniform cross sections, the 0pposite sides of said adjacent membersbeing struck from different centers to cause said passages to convergetowardsaid second-named opening.

2. A heat interchanger for a boiler including, in combination, anenclosure member having a chamber and. being provided with a relativelywide opening in one end constituting a passage for the ingress of thecombustion gases and an oppositely disposed opening for the egress ofsaid gases, hollow members extending through said enclosure memberhaving arcuate sides, the adjacent sides of adjacent members beinglocated about a common center to provide passages having uniform widthand the center member being elliptical in cross section for eifectingthe converging of the passages toward said secondnamed opening.

3. A heat 'interchanger for a boiler including, in combination, anenclosure member of generally circular section provided with a chamberand having a narrow arcuate opening which encompasses substantially onehalf of the circumference of the chamber for constituting a passage forthe ingress of the combustion gases, said enclosure being provided witha second opening oppositely disposed with respect to said first namedopening for the egress of said gases, and tubular members extendingthrough said enclosure member, said tubular members having fiatconverging sides with. a side of each tubular member disposed inparallel relation to a side of an adjacent member for effecting passagestherebetween, the passages converging radially toward said secondopening.

4. A furnace including a casing, a hollow wall intermediate the top andbottom of said casing dividing it into a lower combustion chamber and anupper heat interchanger chamber, a passage between said combustionchamber and one side only of said interchanger chamber, saidinterchanger chamber having a discharge opening on the side thereofopposite said passage, a second casing surrounding the first mentionedcasing in generally spaced relation thereto and the space between saidcasings being connected to the interior of said hollow wall, and aplurality of separate hollow tubes extending between said top and saidwall connecting the interior of said wall with the space between saidtop and said second casing, each of said hollow tubes being elongatedintransverse section in the direction of the flow of gases between saidpassage and opening, and the sides of adjacent tubes being so locatedrelative to each other to form aplurality of relatively narrowseparatedpassages elongatedin said direction of flow for the passage of saidgases.

5. A furnace including a casing, a hollow wall intermediate the top andbottom of said casing dividing it into a lower combustion chamber and anupper heat interchanger chamber, a passage between said combustionchamber and one side only of said interchanger chamber, saidinterchanger chamber having a discharge opening on I the side thereofopposite said passage, a second casing surroundingtlie firstmentionedcasing in generally spaced relation thereto and the spacebetween said casings being connected to the interiorof said hollow wall,and a plurality of separate hollow tubes extending between said top andsaid wall connecting the interior of said wall with the space betweensaid top and said second casing, each of said hollow tubes being elongated in transverse section in the direction of the flow of gasesbetween said passage and opening, and the cross sectional width of saidtubes measured in a direction perpendicular to said direction of flowdecreasin toward the edge thereof closets to said discharge opening.

6. A furnace including a casing, a hollow wall intermediate the top'andbottom of said casing dividing it into a lower combustion chamber and anupper heat interchanger chamber, a passage between said combustionchamber and one side only of said interchanger chamber, saidinterchanger chamber having a discharge opening on the side thereofopposite said passage, a second casing surrounding the first mentionedcasing in generally spaced relation thereto and the space between saidcasings being connected to the interior of said hollow wall, and aplurality of separate hollow tubes extending between said top andsaidwall connecting the interior of said wall with the space betweensaid top and said second casing, each of said hollow tubes beingelongated in transverse section in the direction of the flow of gasesbetween said passage and opening, the sides of adjacent tubes being solocated relative to each other to form a plurality of relatively narrowseparated passages elongated in said direction of flow for the passageof said gases, and the width of said tubes decreasing toward saidopening whereby the thickness of the medium therein to be heated,measured in a direction perpendicular to said direction, varies inaccordance with the decrease in heat content of the gases flowingthrough said elongated passages.

7. A furnace including a casing, a hollow wall intermediate the top andbottom of said casing dividing it into a lower combustion chamber and anupper heat interchanger chamber, a passage between said combustionchamber'and one side only of said interchanger chamber, saidinterchanger chamber having a discharge opening on the side thereofopposite said passage, a second casing surrounding the first mentionedcasing in generally spaced relation thereto and the space between saidcasings being connected to theinterior of said hollow wall, and aplurality of separate hollow tubes extending between said top and saidWall connecting the interior of said wall with the space between saidtop and said second casing, each of said hollow tubes being elongated intransverse section in the direction of flow of gases between saidpassage and opening, and the sides of adjacent tubes being so locatedrelative to each other to form a plurality of relatively narrowseparated passages elongated in said direction of flow for the passageof said gases, some of said tubes being elongated in said transversesection to a greater extent than others of said tubes.

8. A furnace including a casing, a hollow wall intermediate the top andbottom of said casing dividing it into a lower combustion chamber and anupper heat interchanger chamber, a passage between said combustionchamber and one side only of said interchanger chamber, saidinterchanger chamber having a discharge opening on the side thereofopposite said passage, a second casing surrounding the first mentionedcasing in generally spaced relation thereto and the space between saidcasings being connected to the interior of said hollow wall, and aplurality of separate hollow tubes extending between said top and saidwall connecting the interior of said wall with the space between saidtop and said second casing, each of said hollow tubes being elongated intransverse section in the direction of the flow of gases between saidpassage and opening, the sides of adjacent tubes being so locatedrelative to each other to form a plurality of relatively narrowseparated passages elongated in said direction of flow for the passageof said gases, and said tubes being arranged with the lengths of saidsections in fan-like relation with respect to said opening.

JAMES A. FORD.

